In impedance cytometry, particle trajectory can influence the measurements obtained. In this review, the physical grounds of this dependence are explained and both the challenges and the opportunities induced by this phenomenon are discussed.

In this review article, we discuss the latest advances and future perspectives of microfluidics for micro/nanoscale catalyst particle synthesis and analysis.

In this work a new method to track particles in microfluidic channels is presented.

The deflection due to the Magnus force of magnetic particles with a diameter of 80 μm dropping through fluids and rotating in a magnetic field was measured. With the Reynolds number for this experiment around 1, we found trajectory deflections of the order of 1°, in agreement with the measurement error in theory. This method holds promise for the sorting and analysis of the distribution in magnetic moment and particle diameter of suspensions of microparticles, such as applied in catalysis, or objects loaded with magnetic particles.

Microparticle porosity is normally determined in bulk manner providing an ensemble average that hinders establishing the individual role of each microparticle. On the other hand, single particle characterization implies expensive technology. We propose to use ion concentration polarization to measure differences in mesoporosity at single particle level. Ion concentration polarization occurs at the interface between an electrolyte and a porous particle when an electric field is applied. The extent of ion concentration polarization depends, amongst others, on the mesopore size and density. By using a fluorescence marker we could measure differences in concentration polarization between particles with 3 nm and 13 nm average mesopore diameters. A qualitative model was developed in order to understand and interpret the phenomena. We believe that this inexpensive method could be used to measure differences in mesoporous particle materials such as catalysts.

High-aspect-ratio nanostructures can improve intracellular delivery through nanopores and enhance electrophysiological recordings by strengthening the physical coupling between cells and underlying micro/nanostructures. However, key properties of this cell–nanostructure interface, especially the seal resistance, remain poorly quantified. Here, we report a wafer-scale “nano-volcano” platform with integrated sub-micropores (800 nm diameter) and 100 nm-thick walls. The device supports cell culture, enables intracellular delivery, and allows direct electrical quantification of the cell/nanostructure seal resistance using low-amplitude DC measurements. These measurements are facilitated by the relatively large pore diameter, which reduces access resistance. The fabrication process is reliable and repeatable at the wafer level, consistently producing open pores and well-formed nano-volcano structures across the entire wafer. As a proof of concept, we cultured human embryonic kidney cells on the nano-volcano array, quantified seal resistance, and achieved intracellular delivery of propidium iodide. Overall, this platform provides a simple, scalable, and quantitative approach to intracellular delivery while enabling new biophysical insight into the cell–nanostructure interface, an insight that could guide improved seal formation in automated patch-clamp systems.